Lena never liked staying after lessons, especially on rainy, stormy evenings. On this day, however, Simon persuaded her to help the history teacher with the archives, in return promising to show her something special. The corridors of the old high school seemed even more deserted with each thunderstorm, and the yellow light of the fluorescent lamps vibrated restlessly on the cracked walls. As they collected old binders, Simon stopped at a metal door in the basement that they had never seen here. It was rusty, clearly older than the rest of the building, and had a strangely carved mark on it resembling a criss-crossing spiral pattern. - What's that? - whispered Lena, looking at the boy with concern. Simon smiled slightly, but the tension was visible in his eyes. - I checked the old map of the school - he said. - This door shouldn't be here. They hesitated for a moment, and the storm outside the window grew stronger. Finally Lena reached out and touched the handle. The metal was icy, and after a moment there was a quiet creak in the silence. The door gave way. Behind them was darkness, punctuated by a single, cold light that flicked somewhere in the depths. Without a word they stepped inside. Broken tiles clattered underfoot, and the air was heavy and electrified, as if a storm had been brewing all along. After a few steps, Lena noticed a strange mist swirling against the walls. With each metre, the light behind them grew fainter, until finally another light flashed up - a purple glow beaming from around the corner. In the silence, footsteps could clearly be heard coming from deep down the corridor. A tall figure in a long, shimmering cloak emerged from around the corner, his face hidden by a hood. The figure stood in front of them, and the mist around them began to thicken, obscuring everything around them. - Who are you? What are you doing here? - a strange, vibrating voice rang out. Lena and Simon looked at each other, their hearts thudding in their chests. In that one moment, they realised they had crossed a world they had no idea existed, but there was no turning back....